An Expanded Set of Amino Acid Analogs for the Ribosomal Translation of Unnatural Peptides
An Expanded Set of Amino Acid Analogs for the Ribosomal Translation of Unnatural Peptides
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DOI：
10.1371/journal.pone.0000972
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发表时间：
2007-10-03
期刊：
影响因子：
3.7
通讯作者：
Szostak, Jack W.
中科院分区：
文献类型：
--
作者：
Hartman, Matthew C. T.;Josephson, Kristopher;Szostak, Jack W.
背景资料。将体外翻译应用于非天然多肽的合成，可能会产生极大的高度修饰多肽文库，这是寻找新药物的先导化合物的潜在来源。然而，翻译装置的专一性限制了非天然氨基酸的多样性，这些氨基酸可以通过核糖体翻译并入多肽中。我们之前已经证明，超过90个非天然氨基酸可以被酶负载到tRNA上。方法/主要调查结果。我们现在已经使用竞争试验来评估这些类似物的tRNA-氨基酰化的效率。我们还使用了一系列的多肽翻译分析来衡量这些类似物被结合到多肽中的效率。该翻译装置可以容忍大多数侧链衍生物，少数α、α二取代、N-甲基和α-羟基衍生物，但不能容忍β-氨基酸。我们发现，50多种非天然氨基酸可以通过核糖体翻译被结合到多肽中。使用一组有效带电和翻译的类似物，我们能够制备包含多达13种不同非天然氨基酸的单肽。结论/意义。我们的结果表明，一系列不同的非自然构建块可以被翻译成多肽。这些构件为用高度修饰的类药物多肽进行体外选择提供了新的机会。
Background. The application of in vitro translation to the synthesis of unnatural peptides may allow the production of extremely large libraries of highly modified peptides, which are a potential source of lead compounds in the search for new pharmaceutical agents. The specificity of the translation apparatus, however, limits the diversity of unnatural amino acids that can be incorporated into peptides by ribosomal translation. We have previously shown that over 90 unnatural amino acids can be enzymatically loaded onto tRNA. Methodology/Principal Findings. We have now used a competition assay to assess the efficiency of tRNA-aminoacylation of these analogs. We have also used a series of peptide translation assays to measure the efficiency with which these analogs are incorporated into peptides. The translation apparatus tolerates most side chain derivatives, a few alpha,alpha disubstituted, N-methyl and alpha-hydroxy derivatives, but no beta-amino acids. We show that over 50 unnatural amino acids can be incorporated into peptides by ribosomal translation. Using a set of analogs that are efficiently charged and translated we were able to prepare individual peptides containing up to 13 different unnatural amino acids. Conclusions/Significance. Our results demonstrate that a diverse array of unnatural building blocks can be translationally incorporated into peptides. These building blocks provide new opportunities for in vitro selections with highly modified drug-like peptides.